Automatic sizing device for a honing machine



Nov. 14, 1967 M. R. EsTABRooK :352,067

V AUTOMATIC SIZING DEVICE FOR A HONING MACHINE Filed March 5o, 1965 l 2sheets-sheetA 1 MVEADTokm/z l5 ark Stab/OOM tjlv-ramsyJ 2 sheets-Shea 2IO @a w \\w\v. l M um, QW, om@

QfTTTO RME Y/ Nov. 14, 1967 M. R. ESTABRCOK v v AUTOMATIC SIZING DEVICEFOR A HONING MACHINE Filed March 30, 1965 United States Patent 3,352,067AUTOMATIC SIZIN G DEVICE FOR A HONING MACHINE Mark R. Estabrook,Rockford, Ill., assignor to Barnes Drill Co., Rockford, Ill., acorporation of Illinois Filed Mar. 30, 1965, Ser. No. 443,876 9 Claims.(Cl. 51-165) ABSTRACT F THE DISCLOSURE An automatic honing machinehaving a reciprocating rotary tool that is progressively expanded withina work bore to feed the honing stones into the bore wall, therebyremoving surface roughness and enlarging the bore to a predeterminedsize. The endwise motion of .the usual expander rod is transmitted to asizing rod supported for movement along a parallel path and magnified bya rack-and-pinion linkage which moves the sizing rod at a substantiallygreater rate toward an adjustable micrometer stop, the stop and thesizing rod constituting the two contact elements of an electric switchwhich, when closed, signals that a preselected amount of tool expansionhas occurred.

This invention relates to a honing machine for enlarging and finishingbore in a workpiece by reciprocating and rotating an expandable honingtool within the bore while gradually expanding the tool to pressabrasive elements thereon against the bore wall. Expansion of the toolis produced by endwise movement of an expander rod carrying a camengaging the inner sides of the abrasive elements and operable duringmovement of the rod in one direction relative to the tool to cam theelements outwardly at ar ate determined by the rate of movement of therod. The invention has particular reference to a device for sensing theattainment of a predetermined bore' size and terminating the honingcycle in a machine having non-wearing honing elements.

The general object of the present invention is to sense the attainmentof a preselected bore size in a novel manner which provides an accurateindication of the changing bore size during honing and eliminates theneed for direct measurement of the bore.

Another object is to utilize the motion of the expander rod as a directand precise indication of the bore size.

A more detailed object is to magnify .the expander rod movement duringexpansion of the tool and transmit the magnified motion to a sizingdevice which measures the magnified motion for precise` measurement ofthe bore size during honing.

The invention also resides in the novel manner of using the sizingdevice to signal the attainment of a preselected bore size.

Other objects and advantages of the invention will become apparent fromthe following detailed descriptions taken in connection with theaccompanying drawings, in which: v

FIG. 1 is a fragmentary front elevational view of a honing machineembodying the novel features of the present invention with parts broken-away and shown in section for clarity of illustration:

FIG. 2 is an enlarged fragmentary side elevation of part of FIG. 1 withother partsrbroken away and shown in section.

FIG. 3 is a schematic perspective view of the expander rod and sizingdevice.

FIG. 4 is an enlarged fragmentary cross-sectional view takensubstantially along the line 4-4 of FIG. 1.

FIG. 5 is a fragmentary front elevation of the machine.

As shown in the drawings for purposes of illustration, the invention isincorporated in a machine for honing a bore wall 10 in a workpiece 11 byreciprocating an expandable tool 12 back and forth through the bore andsimultaneously rotating the tool with abrasive elements or stones 13thereon pressed against the bore wall. In this instance, the tool issupported on the lower end of a shank 14 carried on a spindle 15journaled at its upper end in a head 17 slidable up and down alongvertical guide rods 18 (FIG. 5) on the machine frame to reciprocate thetool Within the bore. During such reciprocation, the spindle is rotatedby a motor (not shown) drivingly connected to the spindle throughgearing shown at 19 in FIG. 5.

The honing tool 12 is formed by a plurality of elongated non-wearingstones 13 fitted in and projecting radially outwardly through a seriesof slots 20 (FIG. 1) angularly spaced Iaround a hollow, generallycylindrical body 21 on the lower end of the shank 14. For example, the

non-wearing stones may be of a well known type composed of diamond gritheld together by a suitable adhesive. Followers 22 on the inner sides ofthe stones engage -a conical cam 23 guided for axial motion in the boredefining the interior of the tool body, and the cam is moved downwardlyrelative to the tool by means of an elongated rod 24 extending coaxiallythrough the shank and connected adjacent its upper end to a suitablemechanism mounted on the head 17 and operable to feed the rod endwiseand downwardly at a controlled rate, the cam being fastened to the lowerend of the expander rod. In this instance, the rod comprises a lowersection 25 carrying the cam, a short intermediate section 27 threadedonto the upper end of the lower section `to permit adjustment of thelength of the expander rod, and an upper section 28 Iabutting againstthe upper end of the intermediate section within a coupling 29 whichforms a universal joint in the spindle. Adjustment of the length of therod is effected by a sleeve 30 rotatably supported on the spindlebetween a downwardly facing shoulder -31 (FIG. 1) thereon and a snapring 32 fitted in a groove below the sleeve. The sleeve iS formed withinternal teeth meshing with a pinion 33 journaled on the spindle asshown in FIG. 1 and meshing Y with external teeth on the intermediatesection. Thus,

turning of the sleeve 30 turns the intermediate section relative to thelower section to extend or contract the expander rod.

The mechanism for moving the expander rod 24 endwise through the spindle15 and the shank 14 may take various forms well known in the art andforming no part of the present invention. For example, it may be areciprocating hydraulic actuator 34 (FIG. 5) at the upper end of theexpander rod, or any other well known type of expansion mechanism. Whenthe upper section 28 of the expander rod is moved upwardly to permitcontraction of the tool, a coiled spring 35, compressed between adownwardly facing shoulder 37 on the lower section 26 and an opposedshoulder 38 on the shank around the expander rod, pushes the lower andintermediate sections upwardly to draw the cam 23 upwardly and away fromthe followers 22.

During the honing cycle, the expander rod 24 is moved downwardly :at acontrolled rate to feed the stones 13 outwardly into the bore wall 10until the bore has been enlarged to the desired size. Then, toolexpansion is terminated and the tool is withdrawn from the finishedbore.

In accordance with the present invention, theV motion of the expanderrod 24 relative to the stones 13 during the honing cycle is used as adirect and precise indication of the changing size of the bore, and thismotion is measured by a novel sizing device 39 which determines when thebore has attained precisely the desired finished size. To these ends, asizing member in the form of a rod 40 is supported on the head 17 forendwise movement along a path spaced from the expander rod and iscoupled to the latter by a drive connection which magniiies or ampliesthe expander rod motion and transmits the magnified motion to the sizingrod to move the latter along its path at a rate precisely correlatedwith but substantially greater than the rate of expander rod movement.

Thus, the position of the sizing rod 40 along its path at all timesduring the honing cycle is directly related to the tool size and boresize at that time. Moreover, a sensing element 41 is mounted along thepath of the sizing rod and adjustably positioned on the frame to producea signal when the sizing rod reaches a preselected point along the path,thereby indicating that the bore has attained the preselected size.

In the present instance, the sizing rod 40 is guided on the head 17 forendwise movement alonga path paralleling the path of the expander rod 24by a vertically disposed sleeve 42 (FIGS. 1 and 2) supported on amounting plate 43 movable with the head along one of the guides 18. Thedrive connection for moving the sizing rod is formed by a rack 44 faston the upper end of the expander rod and meshing with a pinion 45 (FIGS.l and 3) on one end of a cross-shaft 47 journaled in the head forrotation about a horizontal axis. The other end portion of thecross-shaft is disposed alongside a second rack 48 on the upper endportion of the sizing rod and meshing with a second pinion in the formof a gear sector 49 supported on the cross-shaft for rotation with thelatter in the plane of the rack 48.

The cross-shaft is journaled in a spacer sleeve 50 (FIGS. 1 and 5)extending through a bracket 51 supporting the mounting plate 43 on theside of the head 17, and the radius of the pinion 49 is substantiallygreater than the lradius of the pinion 45. A shoe 52 (see FIG. 2)adjustably supported on the mounting plate by bolts 53 overhangs therack 48 and holds the latter in meshing engagement with the associatedpinion.

With this arrangement, downward motion of the expander rod 24 istransmitted by the rack 44 and the pinion 45 to the cross-shaft 47 andthence to the rack 48 through the pinion 49 while being magnified oramplied as a result of the substantial difference in pinion sizes. Thus,the sizing rod 40 is moved downwardly with the expander rod but at asubstantially greater rate capable of being sensed with much greateraccuracyv than the slower motion of the expander rod.

To sense the position of the sizing rod 40 and signal the attainment ofa preselected bore size, the element 41 is a micrometer mounted formovement with the head 17 on a sleeve 54 (FIGS. 1 and 5) slidable alongone of the guides 18 and positioned along the path of the sizing rod forengagement therewith when the rod reaches a preselected position alongits path. As shown most clearly in FIG. 1, the micrometer is threadedthrough an L- shaped bracket 55 on the sleeve 54 in axial alinement withthe sizing rod for adjustment toward and away from the latter by turningot' the micrometer relative to the bracket. Thus, the upper end 57 ofthe micrometer forms a stop engageable with the leading end 58 of thesizing rod during downward movement of the latter, and the position ofthe stop is adjustable to vary the position in which the sizing rodengages the stop.

In the present instance, the sizing signal is produced automatically asan incident to engagement of the sizing rod 40 and the micrometer 41.For this purpose, the micrometer and the rod constitute the two contactelements of an electric switch which is closed upon engagement of thesetwo elements to ,complete a circuit from a source 59 through a relay 60in the control circuits of the machine. This is accomplished byelectrically insulating the rod from the rack 48 by means of a plasticplug 61 (see FIG. 4) having a central cylindrical portion dividing thesizing rod and oppositely extending studs 62 telescoped into and securedto the rack and the sizing rod. Thus, the plug suspends the rod from therack while, at the same time, preventing metal-to-metal contact at thejoint. In addition, the rod is connected to the relay 60 through aconductor 63 fastened to the rod at 64, and the micrometer is grounded,as indicated schematically in FIG. 3, so that engagement of the rod andthe micrometer completes the circuit from the source through the relay,the conductor and the rod to the micrometer. The operation of the relaymay be used in various well known Ways to terminate the honing cycle.

In addition to controlling the termination of hone expansion, the sizingrod motion may `be sensed at an intermediate stage during the expansionand used to terminate the initial rapid expansion of the toolcustomarily used to bring the stones 13 close to or against the borewall 10 and then to initiate slow feeding of the stones into the wall.For this purpose, a cam 65 is provided on the sizing rod intermediatethe ends of the latter for engagement with a follower 67 which operatesa switch 68 mounted alongside the rod, the follower being disposed alongthe path followed by the cam during expansion of the tool. Herein, thecam is a conical surface formed on the leading end of a cylindrical nut69 threaded onto the sizing rod and thus capable of being adjusted alongthe sizing rod to vary the point of actuation of the switch 68. A setscrew 70 (FIGS. 2 and 3) holds the nut in diierent selected positionsalong the rod.

In operation, the nut 69 and the micrometer 41 are adjusted to selectedpositions relative to the sizing rod 40 and the bracket 55,respectively, and the rapid expansion actuator (not shown) is startedwith the honing tool 12 contracted. Thus, the expander rod 24 begins tomove downwardly relative to the tool at a rapid rate, and therack-and-pinion connections transmit this motion to the sizing rod tomove the latter downwardly at an even faster rate. When the stones areclose to the bore wall, the cam 65 actuates the switch 68 and beginslower movement of the expander rod. Of course, the stop 57 is spacedfrom the lower end 58 of the sizing rod at this time a distancecorrelated with the amount of slow tool expansion required to bring thebore up to the desired size.

Then, as the bore wall 10 is worn away and the bore is graduallyenlarged, the sizing rod 40 approaches the micrometer stop 57 at a ratesubstantially greater than the rate of expander rod movement andeventually engages the stop, completing the circuit through the relay 60and thereby signaling that the bore has attained precisely the sizedesired.

I claim as my invention:

1. In a honing machine, the combination of, a support, an expandablehoning tool having non-wearing honing elements mounted on said supportfor back and forth reciprocation and, simultaneous rotation to hone aWork bore, an expander rod supported for endwise movement relative tosaid tool during reciprocation and rotation and operable upon movementin one direction to expand the.

tool at a rate determined by the rate of expander rod movement, a sizingrod supported for endwise movement` along a path spaced from andparalleling said expander rod, means connecting said rods and operableto magnify the motion of said expander rod and transmit the magniedmotion to said sizing rod, a stop positioned along said path forengagement with the leading end of said sizing rod during expansion ofsaid tool, means for sensing engagement of said sizing rod and said stopand producing a signal indicating that said tool has been expanded apredetermined amount, and mechanism for adjusting the position of saidstop along said path to vary the position in which said sizing rodengages said stop.

2. The combination defined in claim 1 in which said connecting meanscomprises racks on said expander and sizing rods meshing respectivelyWith a pinion and la gear mounted on a cross-shaft, the gear meshingWith the rack on said sizing rod and having a substantially greaterradius than the pinion meshing with the rack on said expander rod.

3. The combination defined in claim 1 in which said sensing means is anelectrical circuit including said sizing rod and said stop and`completed by engagement of the sizing Irod and the stop.

4. The combination defined in claim 3 in which the leading end portionof said sizing rod is electrically insulated from said connecting meansand is a portion of said circuit.

5. The combination defined in claim 1 further including ra cam on saidsizing rod between the ends of the latter, and a follower positionedalong the path of said sizing rod during expansion of said tool forengagement with said cam before said leading end engages said stopthereby to indicate an intermediate stage in the expansion of said tool.

6. The combination delined in claim 5 in which said cam is formed on anut threaded onto said rod for selective adjustment along the Irod tovary the point of engagement of the cam and said follower.

7. In a honing machine, the combination of, a support, an expandablehoning tool mounted on said support for back and forth reciprocation tohone a Work bore, an expander rod support for endwise movement relativeto said tool during such -reciprocation and operable upon movement inone direction to expand the tool at a rate determined by the rate ofexpander rod movement, a sizing rod mounted for endwise movement along apath spaced Afrom said expander rod, means for magnifying the movementof said expander rod and transmitting t-he magnified movement to saidsizing rod to move the latter along said path at a rate preciselycorrelated with but greater than the rate of expander rod movement, asensing element disposed along said path for engagement With said sizingrod, mechanism for adjusting said element along said path to vary theposition in which said sizing rod engages said element, and meansoperable in response to engagement of said sizing rod and said elementto produce a signal indicating that the tool has attained a preselectedsize.

8. In a honing machine, the combination of, a support, an expandablehoning tool mounted on said support for back and forth reciprocation tohone a work bore, an expander rod supported for endwise movementrelative to said tool during such reciprocation and operable uponmovement in one direction to expand the tool at a rate determined by therate of expander rod movement, a sizing rod mounted for endwise movementalong a path spaced from said expander rod, means for magnifying themovement of said expander rod and transmitting the magnified movement tosaid sizing rod to move the latter along said path at a rate preciselycorrelated with but greater than the rate of expander rod movement, andmeans for sensing the motion of said sizing rod and producing a signalwhen the latter reaches `a predetermined point along said path duringexpansion of said tool thereby indicating that the tool has attained apredetermined size.

9. In a honing machine, the combination of, a support, an expandablehoning tool mounted on said support for back .and forth reciprocation tohone a work bore, an expander rod supported for endwise movementrelative to said tool during such reciprocation and operable uponmovement in one direction to expand the tool at a rate determined by therate of expander rod movement, a sizing member movable back and forthalong a predetermined path spaced yfrom said expander rod, means formagnifying the motion of the rod and transmitting the magnified motionto said sizing member, and means for sensing the motion of said sizingmember and producing a signal when the member reaches a predeterminedpoint along said path during expansion of said tool thereby indicatingthat the bore has attained a predetermined size.

References Cited UNITED STATES PATENTS 2,377,310 6/ 1945 Caldwell et al.51-34 2,386,901 10/ 1945 Kline 51-34 2,631,414 3/ 1953 Muehling 51-34LESTER SWINGLE, Primary Examiner.

7. IN A HONING MACHINE, THE COMBINATION OF, A SUPPORT, AN EXPANDABLEHONING TOOL MOUNTED ON SAID SUPPORT FOR BACK AND FORTH RECIPROCATION TOHONE A WORK BORE, AN EXPANDER ROD SUPPORT FOR ENDWISE MOVEMENT RELATIVETO SAID TOOL DURING SUCH RECIPROCATION AND OPERABLE UPON MOVEMENT IN ONEDIRECTION TO EXPAND THE TOOL AT A RATE DETERMINED BY THE RATE OFEXPANDER ROD MOVEMENT, A SIZING ROD MOUNTED FOR ENDWISE MOVEMENT ALONG APATH SPACED FROM SAID EXPANDER ROD, MEANS FOR MAGNIFYING THE MOVEMENT OFSAID EXPANDER, ROD AND TRANSMITTING THE MAGNIFIED MOVEMENT TO SAIDSIZING ROD TO MOVE THE LATTER ALONG SAID PATH AT A RATE PRECISELYCORRELATED WITH BUT GREATER THAN THE RATE OF EXPANDER ROD MOVEMENT, ASENSING ELEMENT DISPOSED ALONG SAID PATH FOR ENGAGEMENT WITH SAID SIZINGROD, MECHANISM FOR ADJUSTING SAID ELEMENT ALONG SAID PATH TO VARY THEPOSITION IN WHICH SAID SIZING ROD ENGAGES SAID ELEMENT, AND MEANSOPERABLE IN RESPONSE TO ENGAGEMENT OF SAID SIZING ROD AND ELEMENT TOPRODUCE A SIGNAL INDICATING THAT THE TOOL HAS ATTAINED A PRESELECTEDSIZE.